Serviço de intercâmbio de material bibliográfico da Biblioteca da Câmara dos Deputados : uma proposta de melhoria que contemple a arquitetura da informação

Proposta de melhoria do Serviço de Intercâmbio da Biblioteca da Câmara dos Deputados a partir da adoção de um novo modelo balizado pela Arquitetura da Informação e que contemple os recursos tecnológicos atualmente disponíveis. Dentre as justificativas para esta proposta estão a necessidade de modernização para manutenção do serviço, um dos pilares do desenvolvimento de coleções; e o alinhamento deste serviço ao comportamento do usuário pela busca de informação, que vem mudando após o advento da internet. A pesquisa é do tipo exploratória que apresenta a revisão de literatura como base para a fundamentação teórica, na qual são discutidos os aspectos teóricos do desenvolvimento de coleções na modalidade de aquisição por doação, realizada por meio do serviço de intercâmbio entre as bibliotecas. No procedimento metodológico foi feito um estudo no Serviço de Intercâmbio da Biblioteca da Câmara dos Deputados para obter os dados estatísticos que quantificam essa atividade. Foi elaborado um questionário, e enviado as 14 bibliotecas da Rede RVBI para conhecer o funcionamento do serviço de intercâmbio em cada uma delas. Com base nas respostas advindas do questionário foi sugerida a criação de um catálogo coletivo de acesso público via web, nos moldes do Portal Estante Virtual, para centralizar e gerenciar as atividades de intercâmbio de publicações. Os objetivos do catálogo são centralizar as informações e substituir um serviço pouco automatizado nas bibliotecas, outros objetivos do catálogo são agilizar a troca de publicações entre bibliotecas, propiciar economia de espaço, de recursos humanos e financeiros ao otimizar as rotinas e promover a democratização das listas de doações para um número maior de bibliotecas.

Desarrollo y optimización de herramientas biotecnológicas para la obtención de material clonal de "Pinus radiata" D. Don

224 p. : il. col.

热障涂层材料性能和失效机理研究进展

热障涂层材料破坏由大尺度屈曲和层离机制产生，而这些机制又是微裂纹形核、扩展及相互连通结果的积累。由于特殊制备工艺和使用环境，材料性能涉及到许多特殊机制。近半个世纪的研究，人们对其性能有了充分认识。综述近几年的研究结果，内容包括：热生长氧化现象及其热力学描述；热生长应力与材料失效的联系；材料破坏机理与性能控制参数组织的联系；微缺陷演化产生的材料屈曲和层离所需的能量释放率；破坏准则、服役寿命预计模型和评价标准等。

Zein instrumentazio eta material erosiko zenuke ingurugiroko analisiak egiten dituen laborategia muntatzeko?

Duración (en horas): Más de 50 horas. Destinatario: Estudiante y Docente

“Deborah Numbers”, Coupling Multiple Space and Time Scales and Governing Damage Evolution to Failure

Two different spatial levels are involved concerning damage accumulation to eventual failure. nucleation and growth rates of microdamage nN* and V*. It is found that the trans-scale length ratio c*/L does not directly affect the process. Instead, two independent dimensionless numbers: the trans-scale one * * ( V*)including the * **5 * N c V including mesoscopic parameters only, play the key role in the process of damage accumulation to failure. The above implies that there are three time scales involved in the process: the macroscopic imposed time scale tim = /a and two meso-scopic time scales, nucleation and growth of damage, (* *4) N N t =1 n c and tV=c*/V*. Clearly, the dimensionless number De*=tV/tim refers to the ratio of microdamage growth time scale over the macroscopically imposed time scale. So, analogous to the definition of Deborah number as the ratio of relaxation time over external one in rheology. Let De be the imposed Deborah number while De represents the competition and coupling between the microdamage growth and the macroscopically imposed wave loading. In stress-wave induced tensile failure (spallation) De* < 1, this means that microdamage has enough time to grow during the macroscopic wave loading. Thus, the microdamage growth appears to be the predominate mechanism governing the failure. Moreover, the dimensionless number D* = tV/tN characterizes the ratio of two intrinsic mesoscopic time scales: growth over nucleation. Similarly let D be the “intrinsic Deborah number”. Both time scales are relevant to intrinsic relaxation rather than imposed one. Furthermore, the intrinsic Deborah number D* implies a certain characteristic damage. In particular, it is derived that D* is a proper indicator of macroscopic critical damage to damage localization, like D* ∼ (10–3~10–2) in spallation. More importantly, we found that this small intrinsic Deborah number D* indicates the energy partition of microdamage dissipation over bulk plastic work. This explains why spallation can not be formulated by macroscopic energy criterion and must be treated by multi-scale analysis.

Variation of flexural strength of cement mortar attacked by sulfate ions

Under the environment of seawater, durability of concrete materials is one of the chief factors considered in the design of structures. The decrease of durability of structures is induced by the evolution of micro-damage due to the erosion of chlorine and sulfate ions, which is characterized by the reduction of modulus, strength, and toughness of the material. In this paper, the variation of the flexural strength of cement mortar under sulfate erosion is investigated. The results obtained in present work indicate that the erosion time, concentration of sulfate solution, and water-to-cement ratio will significantly affect the flexural strength. Crown Copyright (c) 2008 Published by Elsevier Ltd. All rights reserved.

On mechanical properties of metallic glass and its liquid vitrification characteristics

A systematic survey of the available data such as elastic constants, density, molar mass, and glass transition temperature of 45 metallic glasses is conducted. It is found that a critical strain controlling the onset of plastic deformation is material-independent. However, the correlation between elastic constants of solid glass and vitrification characteristics of its liquid does not follow a simple linear relation, and a characteristic volume, viz. molar volume, maybe relating to the characteristic size of a shear transformation zone (STZ), should be involved.

Experimental investigation of Very-High-Cycle Fatigue behavior for a structural steel

Very-High-Cycle Fatigue (VHCF) test for a medium carbon structural steel (40Cr) has been performed and a stepwise S-N curve was obtained by employing cantilever-type rotary bending fatigue machine with hourglass shape specimen. The S-N curve was well explained as a combination of curves for surface-induced fracture and interior inclusion-induced fracture with fish-eye patterns. The morphology of the fish-eye pattern was illustrated in order to clarify subsurface crack initiation and propagation behavior.